Hi @CountryHaven ,
We have both the Australorps's and the red stars in our mixed flock. Just like anything else, both have their plusses and minuses. With both breeds, you'll have a nice flock.
The sex links are egg laying machines. We get huge darkish brown eggs from ours almost every single day. They are curious, friendly and outgoing birds. I've read that because of their high egg output, they can suffer from health issues and won't live as long as other breeds but since ours are only 1 year old, we haven't experienced any of that. One thing I've noticed with all 3 of our sex link girls, they peck! Not to be mean but more to get attention to be picked up or fed extra treats. None of our other birds do that, weird.
The Australorps that we have are beautiful birds with their glossy black feathers, they pick up highlights of beetle green in the sun. We started with 4 and 2 died suddenly and unexpectedly so down to the last 2 of them. One of them is a bit of a bully and the other one is at the bottom of the pecking order. They are good layers, not as large of eggs as the sex links but lay nice eggs regularly. The ones we have had have not been the friendliest and don't like to be touched. I know others have had the exact opposite experience with theirs, but ours are standoff-ish. While these have been ok birds for our flock, once they are gone, I won't get them again. But, other folks have had a totally different experience with theirs so every bird is different.
That's my story, it will be interesting to see what other owners have to say about theirs. Good luck to you in your new adventure.
Wish you all the best!